Rust inhibiting composition



Patented Mar. 24, 1953 U N I TED STAT ES T ()F F I'QE- i 2,632,709" v RUST INHIBITING GOMPOSITION Knapel-F. Schiermeier, Alton, andPaulWL Jones,

EastAlton; 111., assignors toshelfDevelopment' Oompany; San Francisco; Calif., a corporation of Delaware No Drawing. Application-July 19, 1949, Serial -No. 105,668

l This invention. relates. to an all-purposefcor rosioninhibitingcomposition; More particularly, this invention pertains to corrosion inhibiting compositions having the ability of forming) on metal'surfaces a tenacious protective film, which" is impervious to moisture and'other contami nants.

It is well'known that'moisture; corrosive fluids andg ases, e. g. HS, S02, etc. readily attackn'ot only metallic surfaces but'non-metallic surfaces and cause corrosion, rusting, pittingfand'ot'her damage tosuch surfaces. Also'a'queous solutions when" in contact with an'letallic'surface readily attack it' and causecor'rosion and'rustingl' Under" certain conditions the problem'of corrosion becomes exceedinglyserious' because. once started it becomes" progressivelyaccelerated; Thus, oils containing small amounts of water 'b'ecomevery' corrosive to contacting metals. This isdue'to' the fact that oils and particularly" liquid petro- 1eumhydrocarbons" arerelatively' good solubil iZers of oxygenandany moisture present therein becomes" surrounded by an almost inexhaustible store'ofoxyg-en; Moisture undensucnconditions' isinhibited from evaporating 'and'since therate of "transfer of oxygen from hydrocarbons, such as mineral oil orgasoline; to water is'limited, ideal conditions'for rusting? and corrosion are setup. The presence 'of' electrolytes and formation of corrosive decomposition products in oils and' the lik'ei'ja'lsof gi'eatly'increase the rate of 'corro'sivity;

Countless" materials" and compositions have been'tri'ed' for'protecting surfaces'by forming on organic compounds; e: g. organic acids; amines;

inorganic co-mp'ounds and the me in order to protect them against? corrosion. Inalmostall cases where no chemical reactionoccurs between the surface'treated and the corrosion or rustinhibitorfverylittle benefit was derived. This is due to the' fact that non-chemical" reactive inhibitors are incapable of penetrating"thesurfaoe being protected and are incapable of displacing the contaminant" therefrom. In cases where such" inhibitors are able to form protective coat-'- ings on surfaces they are easily. displaced by moisture or rupture readily. They. are relatively ineffective against corrosive acidic materials and gases such as are formed during operation of combustion and turbine engines and are easily destroyed when applied to surfaces which are subjected 'to high temperatures.

' It has'now been discoveredthat variousmetallic" surfaces can be protected" against'corro="- sion'by coating'said surfaceslwitha' composition" comprising a major-amount of a mixture, in sub stantially equalportions, of a" light hydrocarbon liquidh'aving awboilin'g point below about 650" F1, e. g. an aromatic solvent and an oxidized waxy" hydrocarbon, said mixture having incorporated therein a minor amount, generally not exceeding. 5% and preferably less than 1%, of "an' organic acid.

The preferred liquid hydrocarbon suitableio'r use in compositions of this invention"are are matic solvents Which'may'be obtained by" any;

suitable means such as the treatmentbfpetro' leum products with various selective solventslior mixtures of solvents which'are adaptedto segregate the relatively morearomatic constituents from the non aroma'tic' constituents. Suitable solvents may. be representedbyv sulfurdioxid; phenol; furfural, nitro-benzene; cresol, aniline; beta,beta' dichloro di'ethyl ether and the like? Hydrocarbons which are particularlysuit'able for treatment with the above type of solvents" are petroleum hydrocarbons having "a boilingrange of'frozn'about 300 F. to"about"600'F: and may bespecifically" represented by" kerosene, gas oil, light hydrocarbon oil fractions and the like? Particularly preferred are 'arom'aticsolvents iob' tainedby'the sulfur dioxide: treatment of a 300 F." to 370 F; petroleum hydrocarboncutaccord= ing to the'well-known Edeleanu process." Char acteristicsof aromatic solvents obtained byisub jecting light petroleum distillateto theiEdeleanu process-are given below:

Aromatic-solvents'*suitablefor use as a com: ponent of compositions of this inventionmay-be obtained by other means than solventex'traotion of petroleumdistilla-ts; Thus aromatic solvents may be obtained from catalytic'convers'ion of petroleumhydrocarbons such as obtained from recyclestocks from catalytiecracking: Also aro' matics such as napththalene, fiuorene, phenan threne anthracene, coal tar' residues 'and the like maybe" admixed in small amountszwith aromatic solvents of-the type described above." The aromatic solvents should: comprise at =1east about 40% of the composition. If desired, part of the aromatic solvent may be replaced with a light liquid hydrocarbon fraction and/or fractions provided the aromatic solvent constitutes a major proportion of the blend and the light liquid hydrocarbon constitutes a minor proportion of the blend. Generally, the aromatic solvent comprises at least two-thirds of the mixture when blended with a light hydrocarbon. Preferably, the aromatic solvent is used as the sole carrier, or diluent for additives of this invention.

The light liquid hydrocarbon fractions which may be blended with aromatic solvents may be obtained from any type of petroleum base such as paraflinic, naphthenic, asphaltic and/or their fractions. The fractions desired are those normally liquid fractions which have a boiling point range below that of lubricating oil. Specific liquid hydrocarbons which may be obtained from petroleum distillate by any suitable means include kerosene, mineral seal oil, mineral spirits,

light spindle oil, light spray oils, petroleum solvent naphtha as well as various other petroleum naphtha cuts, petroleum ethers, octane, isooctane, dodecane; cycloparafiins, e. g., cyclohexane, methylcyclohexane, etc.

The oxidized substantially non-aromatic waxy hydrocarbons may be obtained from hydrocarbon in the manner fully described hereinbelow. Waxy hydrocarbons also may be obtained by polymerization of olefinic materials by the Fischer-Tropsch process or by dehydration of long-chain aliphatic alcohols and oxidizing said materials.

Waxy hydrocarbons may be recovered from suitable petroleum fractions such as Pennsylvania crude, East Texas crudes, Mid-Continent crudes, and the like, by de-asphaltizing the hydrocarbon and thereafter removing the wax from the asphalt-free hydrocarbon fraction by any known suitable means. The asphalt may be separated from the oil either by distillation or solvent extraction and used as a component of composition of this invention. In the solvent process a solvent is selected in which the oil is relatively soluble but in which the asphaltic materials are relatively insoluble. Among such solvents are the light liquid hydrocarbons such as ethane, propane, butane, as well as naphtha and gasoline. Oils treated with such solvents extract the oil and wax leaving behind the asphaltic materials as residue which can be utilized as a component of composition of this invention. The wax-oil mixture may be removed from the asphalt-free solution by chilling the solution, and then separating the precipitated wax by settling, filtering or centrifuging. Waxy materials thus produced are known in the art as slop Waxes, petrolatum stock, slack waxes, scale waxes, parafiin waxes, malcrystalline and needle waxes, micro-crystalline waxes and the like. These Waxes are differentiated from each other by the degree of de-oiling to which they are subjected and all of them may be used provided they are substantially free from aromatics.

De-waxing or separation of the above waxy constituents from the oil may be accomplished by selective solvent treatment using as the diluents liquefied normally gaseous hydrocarbons such as propane, butane, and other corresponding olefins and/or their mixtures as well as oxygen-containing liquid organic substances such as alcohols, ethers, esters, ketones, aldehydes, acids and/or their mixtures. These may include methyl, ethyl, propyl, butyl, amyl alcohols,

methyl or methylethyl ether, acetones, diethyl, dimethyl and methylisobutyl ketones and the like. Chlorinated hydrocarbons such as carbon tetrachloride or trichloroethylene and mixtures of chlorinated hydrocarbons as mentioned above also may be used.

The first step in obtaining waxy constituents from petroleum crudes, for example, such as Mid- Continent crude, is to treat said crude with about six volumes of liquid propane so as to remove the asphalt. The propane from the propane-oil solution is vaporized so that the ratio of propane to oil is reduced approximately 2 to 1. The solution is then chilled to about 40 F. and lower, causing separation of the wax from the oil. The wax can be removed by filtration and the propane separated from the de-asphalted and dewaxed oil and waxy material by distillation.

Waxy materials can also be recovered from the distillate or residuum lube oil fractions and these wax fractions can be split still further into special wax cuts having desired characteristics by use of selective solvents. This is based on a difference in solubility of different waxy fractions in a given solvent. Thus, when using a methylethyl ketone type solvent the aromatic constituents can be removed by successively cooling the mixture down to between about 40 F. and 76 F. so as to remove the aromatics which become substantially soluble in the solvent as the temperature is lowered, while the straight-chain waxes and isoparaffins become substantially insoluble in the solvent. The straight-chain waxes can be separated from the isoparafiins by extraction and fractional crystallization. Depending upon the distillate cut used waxes of from 12 to above 36 carbon atoms and higher can be obtained.

The above type of waxy hydrocarbons may be admixed with synthetic waxes produced by polymerization of olefins under pressure or by dehydrating long-chain fatty alcohols such as octadecyl alcohol and the like. Admixed with nonaromatic waxy hydrocarbon may be minor amounts of waxy materials obtained from nonhydrocarbon services such as marine or animal waxes, vegetable waxes and the like, and specifically may be illustrated by spermaceti, Japan wax, carnauba wax, montan wax, sugar cane wax, cotton wax, etc. and the mixture oxidized.

Instead of subjecting the above liquid hydrocarbons to a dewaxing and solvent extraction process in order to obtain the above disclosed waxy hydrocarbons, residual oils containing the desired waxy constituents after removal of the distillates can also be used. These residual fractions need not be subjected to solvent extraction or dewaxing but must be oxidized in the manner proposed in the succeeding paragraph.

The waxy material and its mixtures may be oxidized by any suitable means such as blowing with an oxidizing gas such as air, air enriched with oxygen, pure oxygen, oxygen diluted with inert gas and the like. Substantially the waxy material may be oxidized by such means as are disclosed in the following U. S. patents: 1,863,004, 2,043,923, 2,156,226, 2,186,910, and 2,216,222. If desired minor amounts not exceeding about one-third, and preferably less, of nonoxidized waxy materials may be admixed with the oxidized products.

The amount of oxidized material used in compositions of this invention is substantially the same as the aromatic solvent used and may vary from 40% to 60%.

Capric, undecylic, lauric, myristic palmitic, stearic,- arachidic, lignoceric, montanic, melistic, oleic, linol-ic; erucic, linolenic, brassidic, stearolic acids, etc. 7

, B VFATTY ACIDS DERIVED FROM Castor oil, cashew nut oil, coconut oil, palm oil, corn il,'cottonseed oil, rapeseed oil, soya bean oil,- codfish oil, herring oil, menhaden oil, sardineoil, seal oil, whale oil, etc.

7 c. SUBSTITUTED FATTY ACIDS I. Hydroxy aliphatic carboa'ylz'c acids Dimethyl hydroxy caprylic, dimethyl hydroxy capric ricinoleic, ricinelaidic, 12-hydroxy stearic 1,10 dihydroxy stearic acid, 4-hydroxy palmitic acid, linusic, sativic, lanoceric, dihydroxy behenic acids, etc. The preferred hydroxy fatty acids are. those in which the hydroxy group is at least 12 carbon atoms removed from the carboxyl'group. i

sang-cos matic fatty acids, etc. The alkyl radical should contain 12 or more carbon atoms. I V

The acids may be used in amounts not exceeding 5% and preferably are used in amounts ranging from 0.25 to 1 by weight.

A general formula of compositions of this invention may be represented as follows:

Essentialadditives: Per centby weight Organic acid and mixtures thereof 0.25-5 Oxidized waxy hydrocarbon -60 Optional additivesye. g., amines, inorganic nitrates, sulfonates, etc- Base aromatic solvent and/or mixture of aromatic solvent and a light liquid hydrocarbon Balance Specific examples of preferred compositions of this invention are:

Composition A:

Per cent by weight Oxidized W. Texas Ellenberger short residue (208 FSP) 47.4 Mineral spirits 521 Oleic acid 0.5

Composition B:

Oxidized W. Texas Ellenberger short residue (260-270 FSP) 45.5 Aromatic solvent 54.0 Oleic acid 0.5

Other composition of this invention can be examplified by the following formulations'in which each component must be within the'critical range set forth above:

Essential Additives:

Oxidized short residue petrolatum Oxidized slop wax Oxidized paraifin wax Oxidized microcrystalline wax. Oxidized slack wax Mixture of oxidized short residue petrolatum and short residue petrolatum Aromatic solvent Mineral spirit Blend of aromatic solvent and kerosene Blend of aromatic solvent and petroleum naphtha oleic acid Castor oil fatty acids Hydrogenated fish oil fatty ac Stearic acid Alkyl succinic acid l Alkyl salicylic acid Optional Additives:

Petroleum sulfonates.

Octadecyl amine. Lithium nitrite Dicyclohexylamine nitrite II. Keto acids Licanic, 12-keto' stearic, 13-keto behenic, jo-

joba oil fatty acids, etc.

III. Miscellaneous acids v Acids produced by oxidation of hydrocarbons, e. g., parafiin wax, mercapto, oleic acid, mercapto stearic acid, amino fatty acids, etc.

D. ALKY LATED POLYCARBOXYLIC ACIDS Succinic, glutaric, adipic, pimelic, suberic, azelaic, tricarballytic, etc. acids. The alkyl radical should contain 12 or more carbon atoms.

- E. *AROMATIC ACIDS i 1atedphthalic alk-ylated salicylic, hydroxy naphthoic, anthranilic, hydroxy substituted aroobtain a more homogeneous and stable product.

In order to determine the protective properties which compositions of this invention possess, metal strips were coated with compositions of this invention and subjected to the following tests. v

. SALT SPRAY TEST 7 Inthis test polished steel panels which have been coated with a desired product to be evaluated are exposed continuously at a constant temperature (95 or 100 F.) to a salt mist or foe which is produced by the atomization of a 20% sodium chloride solution. The average time until rusting occurs on the faces of the panels is taken as the life of the coating.

ULTRAVIOLET WEATHERING UNIT TEST In this test polished or sandblasted steel panels which have been coated with a desired product to be evaluated are continuously exposed to intense light from a carbon arc and are intermittently wetted by a fine water spray. The average time until rusting occurs on the faces of the panels is taken as the life of the coating.

TEST RESULTS Composition Test Results Composition B Salt Spray 20%, days No rust. CompositionX Rust. Composition B Ultraviolet Weathering Unit No Rust.

Test, 25 days. Composition X Rust.

1 Composition X consists of equal parts of oxidized wax and arcmatic solvent.

.vention as hereinbefore set forth may be made without departing from the spirit and scope thereof and, therefore, only such limitation should be imposed as indicated in the appended claims.

We claim as our invention:

1. A rust-inhibiting composition of matter consisting essentially of the following constituents in the following proportions:

Per cent by weight Oxidized short residue petroleum wax 45.5 Aromatic solvent 54.0 Oleic acid 0.5

2. A rust-inhibiting composition of matter consisting essentially of the following constituents in the following proportions:

Per cent by weight Oxidized short residue petroleum wax 47.4

Mineral spirit 52.1 Oleic acid 0.5

3. A rust-inhibiting composition of matter consisting essentially of the following constitucuts in the following proportions:

Per cent by weight Oxidized wax hydrocarbon 40-60 Higher aliphatic carboxylic acid containing at least 10 carbon atoms per molecule 0.255 Light liquid petroleum stock boiling below 650 F Balance v 4. A composition of matter adapted for use as a rust inhibitor consisting essentially of a blend of equal parts by weight of an oxidized short residue petroleum wax and an aromatic solvent, said blend having incorporated therein from about 0.25% to about 5% by weight of oleic acid.

5. A composition of matter adapted for use as a rust inhibitor consisting essentially of a blend of equal parts by weight of an oxidized short residue petroleum Wax and mineral spirits, said blend having incorporated therein from about 0.25% to about 5% by weight of oleic acid.

6. A composition of matter adapted for use as a rust inhibitor consisting essentially of a blend of about equal parts by weight of an oxidized short residue petroleum wax and a light liquid petroleum stock boiling below 650 F., said blend having incorporated therein from about 0.25% to about 5% by weight of a higher aliphatic carboxylic acid having at least 10 carbon atoms.

7. A composition of matter adapted for use as a rust inhibitor consisting essentially of a blend of about equal parts by weight of an oxidized wax hydrocarbon and a light liquid petroleum stock boiling below 650 F., said blend having incorporated therein from about 0.25% to about 5% by weight of an alkyl succinic acid, said alkyl radical having at least 12 carbon atoms.

8. A composition of matter adapted for use as a rust inhibitor consisting essentially of a blend of equal parts by weight of an oxidized wax hydrocarbon and a light liquid petroleum stock boiling below 650 F., said blend having incorporated therein from about 0.25% to about 5% by weight of an alkyl substituted polycarboxylic acid said alkyl substituent containing at least 12 carbon atoms.

9. A composition of matter adapted for use as a rust inhibitor consisting essentially of a blend of equal parts by weight of an oxidized petroleum slop wax and a light liquid petroleum stock boiling below 650 F., said blend having incorporated therein from about 0.25% to about 5% by weight of a soluble higher aliphatic carboxylic acid containing at least 10 carbon atoms per molecule.

10. A composition of matter adapted for use as a rust inhibitor consisting essentially of a blend of equal parts by weight of an oxidized parafiin wax and a light liquid petroleum stock boiling below 650 F., said blend having incorporated therein from about 0.25% to about 5% by weight of a soluble higher aliphatic carboxylic acid containing at least 10 carbon atoms per molecule.

11. A composition of matter adapted for use as a rust inhibitor consisting essentially of a blend of about equal parts by weight of an OXldlZBd short residue petroleum wax and aromatic solvent, said blend having incorporated therein from about 0.25% to about 5% by weight of an alkyl succinic acid, said alkyl radical having at least 12 carbon atoms.

12. rust-inhibiting composition of matter consisting essentially of the following constituents 111 the following proportions:

I Percent by weight Oxidized wax hydrocarbon 13. A rust-inhibiting composition of matter 9 consisting essentially of the following constituents in the following proportions:

Percent by weight 14. A rust-inhibiting composition of matter consisting essentially of the following constituents in the following proportions:

Percent by weight Oxidized short residue petrolatum 40-60 Higher aliphatic carboxylic acid, having at least 10 carbon atoms per molecule 0.25-5 Light liquid petroleum stock boiling below 650 F. Balance KNAPEL F. SCHIERMEIER. PAUL W. JONES.

REFERENCES CITED- The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,184,952 Zimmer et a1 Dec. 26', 1939 2,196,261 Howland et a1. Apr. 9, 1940 2,348,715 Adams et a1 May 16, 1944 2,359,738 Schiermeier Oct. 10, 1944 

3. A RUST-INHIBITING COMPOSITION OF MATTER CONSISTING ESSENTIALLY OF THE FOLLOWING CONSTITUENTS IN THE FOLLOWING PROPORTIONS: 